Reevaluation by CRISPR-Cas9 approach reveals multiple lincRNAs dispensable for pluripotency maintenance and SNORA73 essential for pluripotency exit (RNA-Seq)

Many lincRNAs have been identified as essential regulators for ESC pluripotency through siRNA-based screening. However, the biological and molecular functions of the large intergenic noncoding RNAs (lincRNAs) remain unclear. Here, we employed CRISPR/Cas9-mediated knockout technology to explore the functions of 8 previously annotated lincRNAs in ESCs. Unexpectedly, it was found that most lincRNAs are dispensable for pluripotency maintenance, cloning formation ability, proliferation and apoptosis in ESCs when we disrupted these lincRNAs individually or in combinations. Single-cell transcriptomic analysis of a set of lncRNA knockout ESCs showed consistent results, indicating that previously observed functions of lincRNAs on ESC pluripotency maintenance may be due to off-targeted effects. Interestingly, deletion and transcriptional repression of linc1343 disrupts embryoid body (EB) differentiation in ESC. Notably, GM17300 and two small RNAs (Snora73a, Snora73b) derived from the lnc1343 locus are highly expressed in ESCs. Further overexpression of Snora73a and Snora73b in linc1343 knockout cells rescue the phenotype, suggesting that snoRNAs derived from linc1343 are the responders for EB differentiation. Taken together, our results demonstrate the divergent effects of lincRNAs on regulating ESC pluripotency and EB differentiation.